P1763 Impact of disproportionate functional mitral regurgitation

Background

Application of the effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) is potentially limited as such lesion-focused metrics inevitably lack flexibility to account for the heterogeneity of left ventricular size and function. A recently proposed conceptual framework seeks to rearrange EROA and RegVol cut-offs according to left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF), introducing the novel term "disproportionate FMR" to describe clinically meaningful FMR.

Methods

To test the impact of disproportionate FMR, we embedded data of 291 heart failure patients with reduced ejection fraction (HFrEF) under guideline directed therapy (GDT) into this framework. Regurgitant Volume and EROA were plotted against LVEDV using bubble plots that also account for the heterogeneity of EF (Figure 1 A and C). The black lines depict a regurgitant fraction (RegFrac) of 50% at the median EF (25%) or Vmax (4.3m/s) of the study population. Thus, above individual center lines (illustrated by different bubble sizes) FMR severity is disproportionate, within the area of measurement uncertainty it is proportionate to LV dilation and below, it is likely non-severe. The degree of uncertainty of proportionate FMR is determined by the imprecision of the measurements defined as 2SDs of regurgitant fraction (±6.6%) per Bland-Altmann analysis.

Results

During a median follow-up of 84 months (IQR 84-136), 166 patients died. Disproportionate FMR was associated with excess mortality (RegVol: HR 1.97, 95%CI 1.38-2.81, P < 0.001; EROA: HR 2.22, 95%CI 1.52-3.22), whereas proportionate FMR was not associated with increased long-term mortality (RegVol: HR 1.04, 95%CI 0.71-1.53, P = 0.83; EROA: HR 1.06, 95%CI 0.71-1.58, P = 0.79; Figure 1B&D).

Conclusions

In this contemporary HFrEF cohort every fifth patient has disproportionate FMR which conveys a two-fold increased risk of mortality which provides evidence for the validity of the conceptual framework. Advancement of the proposed framework to clinical practice has several implications: 1)EROA and RegVol are metrics that do not account for the contextual variability of LVEDV and EF. 2)The RegFrac -not incorporated in ESC guidelines but integrated in AHA/ACC definitions- provides a metric proportionated to left ventricular size and function supporting its use to define relevant FMR. However, technical limits suggest its complementary use on top of more robust metrics such as EROA and RegVol. Future studies need to clarify whether disproportionate FMR reflects the subgroup of patients that benefit from mitral valve repair, and provide a robust algorithm that integrates the metrics of FMR severity in a complementary manner.

Abstract P1763 Figure.

P1580 Global regurgitant volume - approaching the critical mass in valvular-driven heart failure

Aims

Recent progress in the diagnosis of functional valve regurgitation forms a coherent perception of severity thresholds by quantitative assessment. However, thresholds focused on either valve in isolation -not accounting for the global hemodynamic burden arising from concomitant functional regurgitation of the mitral and tricuspid valves. We sought to determine whether the global regurgitant volume is associated with adverse cardiac remodeling and mortality.

Methods and results

This long-term observational study included 414 patients on guideline-directed medical therapy. Baseline global regurgitant load defined as the sum of mitral and tricuspid regurgitant volume was assessed by the proximal flow convergence method. All-cause mortality during five years follow-up served as the primary endpoint. The median global regurgitant load was 30ml (IQR 15-49) with 67% accounting for mitral and 33% accounting for tricuspid regurgitant volume. The global regurgitant load had significant impact on outcome with a crude HR of 1.46 (1.28-1.66; P < 0.001) for a 1-SD increase in global regurgitant volume, results that remained virtually unchanged after bootstrap or clinical confounder-based adjustment (P < 0.001 for adjusted models). Spline curve analysis showed a linearly increasing risk with a threshold of 50ml and sustained increasing risk thereafter.

Conclusions

The present study demonstrates the detrimental effect of the global regurgitant load in patients with HFrEF. The threshold where heart failure is driven by the valve lesions is a global regurgitant volume of 50ml with continuously increasing risk beyond that threshold. Future studies need to address whether an attempt to reduce the global regurgitant volume can improve outcome.

Abstract P1580 Figure 1 - Global RegVol

Transcatheter Caval Valve Implantation of the Tricento Valve for Tricuspid Regurgitation Using Advanced Intraprocedural Imaging

A 75-year-old patient with previous mitral and tricuspid reconstruction experienced severe tricuspid regurgitation. On the basis of a prohibitive surgical risk, an interventional heterotopic tricuspid valve implantation was planned. Implantation was performed using fusion-imaging, which facilitated intraprocedural navigation. At 6-month follow-up, the patient presented in improved condition with reduced symptoms. (Level of Difficulty: Advanced.).

Phenotyping progression of secondary mitral regurgitation in chronic systolic heart failure

BACKGROUND

Secondary mitral regurgitation (sMR) drives adverse cardiac remodelling in patients with heart failure with reduced ejection fraction (HFrEF). Progression in severity over time contributes to a transition towards more advanced HF stages. Early identification of patients at risk for sMR progression remains challenging. We therefore sought to assess a broad spectrum of neurohumoral biomarkers in patients with HFrEF to explore their ability to predict progression of sMR.

METHODS

A total of 249 HFrEF patients were enrolled. Biomarkers encompassing key neurohumoral pathways in heart failure were sampled at baseline, and sMR progression was assessed over 3 years of follow-up.

RESULTS

Of 191 patients with nonsevere sMR at baseline, 18% showed progressive sMR within three years after study enrolment. Progression of sMR was associated with higher levels of MR-proADM (adj.OR 2.25, 95% CI 1.29-3.93; P = .004), MR-proANP (adj.OR 1.84, 95% CI 1.14-3.00; P = .012), copeptin (adj.OR 1.66, 95% CI 1.04-2.67; P = .035) and CT-pro-ET1 (adj.OR 1.68, 95% CI 1.06-2.68; P = .027) but not with NT-proBNP (P = .54).

CONCLUSION

Increased plasma levels of neurohumoral cardiac biomarkers are predictors of sMR progression in patients with HFrEF and add easily available incremental prognostic information for risk stratification. Importantly, NT-proBNP was not useful to predict progressive sMR in the present analysis. On the contrary, MR-proANP, primarily produced in the atria, copeptin partly triggered by intra-cardiac and intra-arterial pressures and MR-proADM, a marker of forward failure and peripheral released vasoactive CT-proET1, increase based on a progressive loading burden by sMR and may thus serve as better predictors of sMR progression.

P896Effects of tafamidis in patients with transthyretin amyloid cardiomyopathy

Background

Transthyretin amyloid cardiomyopathy (ATTR-CA) is caused by deposition of amyloid fibrils in the myocardium. The deposition occurs when transthyretin (TTR) becomes unstable and misfolds. Tafamidis is a kinetic stabilizer of TTR that prevents tetramer dissociation and amyloidogenesis by TTR.

Methods

Eighteen patients with diagnosis of ATTR-CA (hATTR or wtATTR) from our national amyloidosis registry were treated with 20 mg of tafamidis for a period of six months. In our explorative analysis we aimed to evaluate the effects of tafamdis by changes from baseline of the serum NT-proBNP concentration, 6-minute walking distance, as well as cardiac structure and function.

Results

The exploratory analysis showed a decrease in serum NT-proBNP concentration in tafamidis treated patients, compared to increase in untreated patients (median difference, −481.0 pg/mL). Tafamidis improved the walking distance during the 6-minute walk test at month six, compared to baseline (mean, 31.25 m). Echocardiographic findings revealed an improvement of the global longitudinal strain (mean, 0.77%), a decrease in left atrial size (mean, −1.65 mm) and a decrease in left ventricular size (mean, −4.13 mm) in tafamidis treated patients compared to untreated patients. Due to insufficient power the results did not differ significantly between tafamidis treated patients and untreated patients.

Change from baseline Tafamidis No treatment Treatment Difference p-value Cardiac Biomarkers n=18 n=15   NT-proBNP, ng/L Baseline, median 2740.0 2835.0 CFB to 6 months, median −207.0 274.0 −481.0 0.329 Functional Status n=8 n=7   6MWT, m Baseline, mean 441.00 420.50 CFB to 6 months, mean 31.25 −16.50 +47.75 0.373 Echocardiogram n=17 n=15   LA, mm Baseline, mean 63.41 61.33 CFB to 6 months, mean −1.65 0.60 −2.25   LV, mm Baseline, mean 44.13 41.80 CFB to 6 months, mean −4.13 0.33 −4.46 0.075   LV wall thickness, mm Baseline, mean 22.06 18.47 CFB to 6 months, mean 0.68 −0.60 +1.28 0.055   Longitudinal strain, % Baseline, mean −10.66 −12.42 CFB to 6 months, mean 0.77 −1.03 +1.80 0.652 MRI n=7 n=6   ECV, % Baseline, mean 52.26 44.22 CFB to 6 months, mean 0.81 3.70 − 2.89 0.493   LV mass, g Baseline, mean 187.71 170.33 CFB to 6 months, mean 24.29 19,67 +4.62 0.612

Conclusion

Treatment with tafamidis for a period of six months in patients with ATTR-CA leads to positive effects on NT-proBNP level, 6-minute walking distance, as well as cardiac structure and function compared to untreated patients.

Refining the prognostic impact of functional mitral regurgitation in chronic heart failure

Aims

Significant efforts are currently undertaken to reduce functional mitral regurgitation (FMR) in patients with chronic heart failure in the hope to improve prognosis. We aimed to assess the prognostic impact of FMR in heart failure with reduced ejection fraction (HFrEF) under optimal medical therapy (OMT) and various conditions of HFrEF. We further intended to identify a heart failure phenotype, where FMR is most likely a driving force and not a mere bystander of the disease.

Methods and results

We prospectively included 576 consecutive HFrEF patients into our long-term observational study. Functional [i.e. New York Heart Association (NYHA) class], echocardiographic, invasive haemodynamic, and biochemical (i.e. NT-proBNP, MR-proANP, MR-proADM, CT-proET-1, copeptin) measurements were performed at baseline. During a median follow-up of 62 months (interquartile range 52-76), 47% of patients died. Severe FMR was a significant predictor of mortality [hazard ratio (HR) 1.76, 95% confidence interval (CI) 1.34-2.30; P < 0.001], independent of clinical (adjusted HR 1.61, 95% CI 1.22-2.12; P = 0.001), and echocardiographic (adjusted HR 1.46, 95% CI 1.09-1.94; P = 0.01) confounders, OMT (adjusted HR 1.81, 95% CI 1.25-2.63; P = 0.002), and neurohumoral activation (adjusted HR 1.38, 95% CI 1.03-1.84; P = 0.03). Subanalysis revealed that severe FMR was associated with poor outcome in an intermediate-failure phenotype of HFrEF i.e. patients with NYHA class II (adjusted HR 2.17, 95% CI 1.07-4.44; P = 0.03) and III (adjusted HR 1.80, 95% CI 1.17-2.77; P = 0.008), moderately reduced left ventricular function (adjusted HR 2.37, 95% CI 1.36-4.12; P = 0.002), and within the second quartile (871-2360 pg/mL) of NT-proBNP (adjusted HR 2.16, 95% CI 1.22-3.86; P = 0.009).

Conclusion

In a patient cohort under OMT, the adverse prognostic impact of FMR is given predominantly in a sub-cohort of a specific intermediate-failure phenotype-well-defined functionally, haemodynamically, biochemically, and morphologically.

P4720Mitraclip XTR device used for the treatment of functional tricuspid regurgitation provides significant reduction of annular size

Background

Tricuspid valve regurgitation (TR) is a progressive disease strongly associated with increased cardiac and all-cause mortality. The transcatheter approach to this pathology has been recently described with promising results in the treatment of symptomatic patients despite optimal medical therapy. Development of annular dilation and leaflet tethering represent a continuous pattern in the pathophysiology of functional TR; for this reason, to reduce and stabilize the annulus is the goal of an efficacious therapy.

Purpose

In order to simplify leaflet grasping, the novel MitraClip XTRdevice has significantly longer clip arms compared to its predecessor. The increased grasping length could be able to apply a radial tension on the tricuspid annulus, reducing it in dimensions. Despite, the increased tension on the leaflets may theoretically impose a higher risk for leaflet tearing We analyzed our single-center experience in order to clarify the capability of the device in the feature of annular reshapement.

Methods

Five high-risk patients (4 females, 72 (quartiles 69–79) y.o., EuroSCORE II 10 (7.25–11.2)% affected by severe symptomatic functional TR were treated with MitraClip XTR implantation in tricuspid position. Right ventricular function was apparently preserved in all cases and the mean sPAP was 41 (quartiles 38–45) mmHg. Perioperative echo-results were collected prospectively and analyzed.

Results

Procedural success (defined as a reduction of more than 1 degree of TR) was achieved in 4 cases (80%). 3±1 devices were implanted per patient in the antero-septal commissure. The tricuspid annular diameter (measured in four chamber view) was reduced from 39 (quartiles 39–41) mm to 31 (quartiles 30–31) mm (p=0.043). Accordingly, the effective regurgitant orifice area (EROA) decreased from 110 (quartiles 70 to 160) mm2 to 45 (quartiles 9–55) mm2 (p=0.02) and the systolic VTI in the hepatic veins decreased by 42%. No significant increase of trans-valvular mean gradients was observed (2.5 (quartiles 2.25 to 2.75)) mmHg vs 3.75 (quartiles 3,75 to 4) mmHg; p=0.2) as well no cases of acute leaflet tearing.

Conclusion

The reduction in tricuspid annulus size with the novel XTRdevice represents an unexpected and interesting achievement of the procedure. A significant reduction of annular dimensions might provide a more durable reduction of functional TR. Long-term follow-up data will be required to clarify these initial results and as well as patient selection criteria.

P6492Quantitative definition of severe functional mitral regurgitation - A matter of intercontinental debate

Background

Recent divergence between AHA/ACC and ESC/EACTS guidelines of the quantitative definition for severe functional mitral regurgitation (sFMR) introduced uncertainty, inconsistency and continuing debate. The relation of each threshold with long-term outcome, in patients under guideline directed therapy (GDT) remains however uncertain.

Methods

We enrolled 269 heart failure patients with reduced ejection fraction (HFrEF) and graded sFMR according to both guideline-recommendations [AHA/ACC: effective regurgitant orifice area (EROA) ≥40mm2 or regurgitant volume (RegVol) ≥60ml/beat and ESC/EACTS: EROA ≥20mm2 or RegVol ≥30ml/beat]. All-cause mortality was defined as the primary endpoint.

Result

According to AHA/ACC guidelines sFMR occurred in 17% by EROA with a median EROA of 0.5mm2 (IQR 0.4–0.6) and in 13% by RegVol with a median RegVol of 76ml/beat (IQR 69–101). According to ESC/EACTS guidelines sFMR occurred in 53% by EROA with a median EROA of 0.4mm2 (IQR 0.2–0.4)and 40% according to RegVol with a median RegVol of 51ml/beat (IQR 37–69). During 8-years follow-up, 165 patients died. We observed a significant association with outcome for sFMR according to AHA/ACC guidelines quantified by EROA (HR 1.66, 95% CI 1.13–2.43, P=0.009; Figure 1A) as well as RegVol (HR 2.02, 95% CI 1.34–3.05, P=0.001; Figure 1A). In contrast, the ESC/EACTS definition of sFMR was related with outcome exclusively if quantified by RegVol (HR 1.46, 95% CI 1.05–2.05, P=0.026; Figure 1B) but not for EROA (HR 1.30, 95% CI 0.91–1.86, P=0.15; Figure 1B).

Figue 1

Conclusion

In this contemporary HFrEF cohort under GDT there is significant association of the ACC/AHA proposed cut-off for severe FMR and long-term mortality. The ESC/EACTS definitions are associated with mortality exclusively for the RegVol. The lack of association between sFMR based on ESC/EACTS EROA cut-offs with mortality potentially results from incorporating patients where the regurgitant burden may still be compensated and has not yet become a driving force of disease progression. Contemporary definition of sFMR entails decision making for surgical/transcatheter repair. Cut-offs need to account for the competing risks of the procedure versus the potential benefit of reducing mortality. Lower thresholds may expose a significant proportion of patients to unnecessary risk of futile procedures and higher thresholds may withhold potentially life-extending therapies. The disagreement between the two guidelines does not only convey a source of uncertainty for treating physicians but also lead to inconsistent treatment allocation thereby hindering comprehensive and comparable research. Future studies need to approximate to the true nature of severe functional mitral valve disease in an attempt to facilitate a unifying definition of sFMR.

P613Cardiac magnetic resonance imaging derived left ventricular mechanical function in patients with atrial fibrillation and left atrial low voltage zones

Background

The relation of left atrial low voltage zones (LVZ) to left ventricular function in patients undergoing pulmonary vein isolation (PVI) is not known.

Objective

To explore the relationship of left atrial low voltage zones (LVZ) on left ventricular function in patients with atrial fibrillation.

Methods

From June to Nov. 2018, 107 (mean age 67y, 70 men, 73 persistent AF) consecutive patients with symptomatic AF underwent a PVI with LVZ mapping. Before PVI the left ventricular ejection fraction (EF) and stroke volume (SV) were measured by cardiac magnetic resonance imaging (CMR). From feature-tracking of CMR-cine images left ventricular global, systolic and diastolic longitudinal strains (GLS), circumferential strains (GCS) and radial strains (GRS) were calculated.

Results

Of 59 patients CMR scanning in sinus rhythm was performed, LVZ were present in 24 patients.

LVEF was significantly lower in patients with left atrial LVZ (62±9% vs. 55±15%) (p=0,03). Left ventricular stroke volume was significantly decreased by the extent of LVZ (94±23 vs. 72±21ml), (p=0,03).

The left ventricular diastolic strains during ventricular filling (caused by atrial contraction) of GLS (r=−0,52), GCS (r=−0,65) and GRS (r=−0,65) were highly signifcantly correlated to the occurence and extent of LVZ (each p<0,001 respectively).

The only systolic ventricular strain was GLS, which decreased (r=−0,3, p=0,03) by the occurance of atrial low voltage.

Conclusion

The active, atrial part of diastolic left ventricular filling properties is impaired by the occurrence and extent of left atrial LVZ. In patients with left atrial LVZ the left ventricular stroke volume and ejection fraction is decreased already in sinus rhythm. It seems possible that atrial mechanical dysfunction and presence of atrial low voltage maybe predicted by LV diastolic strain analysis.

P2727Hemodynamic profiles in patients with cardiac amyloidosis

Background

Intracardiac filling and pulmonary arterial pressures play a central role in various heart failure entities, as they are strong predictors of outcome. However, their role in patients with cardiac amyloidosis (CA) is less clear.

Purpose

We aimed to characterize hemodynamic profiles of CA patients and assess their association with outcomes.

Methods

The present study was conducted within a prospective, national CA registry.

Patients underwent invasive hemodynamic, clinical, laboratory, and echocardiography assessment, as well cardiac magnetic resonance imaging with T1-mapping. The main outcome measure was a combined endpoint consisting of hospitalization for heart failure or cardiovascular death.

Results

Between March 2012 and October 2018, 63 consecutively recruited CA patients underwent invasive hemodynamic profiling. Of those, 36 had cardiac transthyretin amyloidosis (ATTR) and 25 cardiac light-chain amyloidosis (AL). In two patients amyloid subtyping was not possible.

Median age of the study population was 74.0 years and the majority were male (61.9%). Almost half of the patients were in New York Heart Association (NYHA) class ≥III (47.6%) and showed elevated N-terminal prohormone of brain natriuretic peptides (NT-proBNP) with a median of 3222 pg/mL. In comparison to AL, cardiac TTR patients were older (75.0 years versus 69.0 years, p=0.004), more often male (80.6% versus 40.0%, p=0.001), less symptomatic (NYHA class ≥III: 38.9% versus 64.0%, p=0.021), and had lower NT-proBNP values (2324pg/mL versus 5151pg/mL, p=0.004).

Hemodynamic profiling revealed significantly increased intracardiac as well as pulmonary arterial pressures (PAP). On an average, pulmonary artery wedge pressure was 20.0mmHg [interquartile range (IQR): 17.0–25.0], mean PAP (mPAP) was 30.0mmHg (IQR: 25.0–37.0), and mean right atrial pressure (mRAP) was 11.0mmHg (IQR: 7.0–16.0). No differences between ATTR and AL patients could be detected (p=0.148, p=0.398, p=0.620). During a median follow-up of 63.0 weeks, 28 study participants (44.4%) reached the combined endpoint. Moreover, cardiac AL patients had significantly more events as their ATTR counterparts (72.0% versus 27.8%, p=0.001). In cardiac ATTR patients, mPAP was significantly associated with outcome [hazard ratio (HR): 1.083, p=0.034, Figure 1A], which was not the case in the AL group (HR: 1.024, p=0.186, Figure 1B). Cardiac output and pulmonary vascular resistance were not associated with outcome. Neither in the ATTR (p=0.144; p=0.063) nor in AL cohort (p=0.420; p=0.115).

Figure 1

Conclusion

Despite differences in the severity of symptoms between cardiac AL and cardiac ATTR patients, no differences with regards to hemodynamic profiles could be detected.

Furthermore, intracardiac filling and pulmonary arterial pressures seem to be of greater clinical importance in cardiac ATTR as compared to cardiac AL, as these parameters were associated with outcome in the first, but not the latter group.

6097Aminoterminal proB-type natriuretic peptide: a key parameter to optimise therapeutic management of low-flow, low-gradient aortic stenosis

Background

B-type natriuretic peptide (BNP) and aminoterminal-proBNP (NT-proBNP) are well established surrogates of LV function impairment. However, data are scarce regarding their prognostic value to risk-stratify patients with classical low-flow, low-gradient aortic stenosis (LFLG-AS, with low left ventricular [LV] ejection fraction).

Methods

The TOPAS study is a prospective observational cohort of 240 patients with aortic valve area <0.6 cm2/m2, mean gradient<40 mmHg and LVEF<50%. True severe AS was adjudicated using flow independent grading schemes.

Results

BNP significantly predicted one-year (area under the receiver operating-characteristic curve [AUC]) 0.62±0.04, p=0.026) but not three-year mortality. After adjustment for the severity of AS, initial treatment (aortic valve replacement [AVR] vs. conservative management [ConsRx]), age, sex and the EuroSCORE (Model#1), BNP-ratio>550 pg/ml had a trend to predict time to death (HR=2.14 [1.00–4.58], p=0.05). In contrast, NT-proBNP ratio significantly predicted both one and three-year mortality (AUC=0.67±0.04 and 0.66±0.05, both p=0.001), and independently predicted time to death (HR=1.39 per 1 unit of Log transformed NT-proBNP [1.11–1.74], p=0.004). In a head-to-head comparison (108 patients with both biomarkers), the AUCs to predict one and thre-year mortality were significantly higher with NT-proBNP versus BNP (p<0.009). NT-proBNP but not BNP independently predicted mortality and significantly improved Model#1 (Likelihood ratio test Chi2=15.95, p<0.001). The category-free net reclassification index of NT-proBNP was 0.71 (p=0.008) versus 0.38 (p=0.15) for BNP. Furthermore, there was a marked survival benefit associated with AVR in patients with NT-proBNP ≥1700 pg/ml (adjusted hazard ratio (aHR) associated to AVR vs conservative management=0.52 [0.31–0.85], p=0.009), while those<1700 pg/ml had excellent one-year survival under ConsRx (only one death [4.5±4.4%] at one year as compared to 23 [37±6.2%] for ConsRx-NTproBNP>1700, aHR=0.11 [0.01–0.83], p=0.033). The survival benefit associated with AVR interacted with NT-proBNP (p<0.001) but not with true or pseudosevere AS (p=0.53 for interaction), suggesting that NT-proBNP might identify moderate AS patients but sufficiently severe valvulo-ventricular disease to justify AVR.

Survival according to NT-proBNP and AVR

Conclusion

NT-proBNP appears to be an excellent biomarker for the clinical purpose of risk-stratifying classical LFLG-AS. A threshold of 1700 pg/ml i.e. close to the diagnostic threshold for heart failure in acute dyspnea, was a strong independent determinant of the survival benefit associated with aortic valve replacement. Our findings suggest that NT-proBNP should be preferred over BNP.

Acknowledgement/Funding

Canadian Institute of Health Research

P5261Feature tracking by CMR: left ventricular dysfunction predicts outcome in heart failure with preserved ejection fraction

Objectives

To investigate the association between global longitudinal strain (GLS) using feature tracking (FT) cardiovascular magnetic resonance imaging (CMR) and prognosis in patients with heart failure and preserved ejection fraction (HFpEF).

Background

Echocardiography-based studies have demonstrated that in HFpEF left ventricular (LV) strain analyses can detect impaired systolic function despite preserved ejection fraction and might also predict outcome. CMR also allows strain analysis using FT and is furthermore the gold standard for assessment of ventricular volumes and ejection fractions. In addition, T1-mapping allows non-invasive tissue characterization. However, the prognostic relevance of FT-CMR is unknown. In addition right ventricular (RV) FT-CMR is poorly investigated.

Methods

Consecutive patients with confirmed diagnosis of HFpEF underwent CMR on a 1.5T scanner. We used dedicated software (cvi42, Circle Cardiovascular Imaging Inc.) for global longitudinal left ventricular strain (LV-GLS) in a 3D and global longitudinal RV strain (RV-GLS) in a 2D model using feature tracking (FT). In addition, we performed uni- and multivariable Cox regression using a combined endpoint of heart failure hospitalizations, and cardiovascular death to determine the prognostic relevance of FT-CMR.

Results

We included a total of 131 HFpEF patients (70.4±8.6 years old, 70.2% female). Median LV-GLS by FT-CMR was −8% [IQR: −10% to 5%] and median RV-GLS was −11.9% [IQR: −16.57% to −12.23%]. LV and RV GLS values were significantly correlated with LV and RV ejection fractions (r=−0.463, p<0.001 for LV, and r=−0.306, p=0.001 and RV, respectively). 77 (58.8%) events were recorded during a follow-up of 42.0±31.4 months. Patients with an LV-GLS worse than the median (−8%) showed a significantly reduced event-free survival rate (log-rank, p=0.009).In a multivariable Cox-regression model correcting for the strongest clinical variables, including age (HR 1.018 [0.985–1.052], p=0.290), GFR (HR 0.987 [0.975–1.000], p=0.055), diabetes (HR 1.696 [1.028–2.799], p=0.039), and 6-min-walking distance (HR 0.997 [0.995–0.999)], p=0.014), LV-GLS remained significantly associated with outcome (HR 1.093 [1.039–1.150], p=0.001) while RV-GLS had no effect on outcome (p>0.05).

Conclusions

In patients with HFpEF, LV-GLS but not RV-GLS by FT-CMR is significantly associated with cardiovascular events.

P2726Extremely boosted prediction of cardiac amyloidosis by routine laboratory paramaters

Background/Introduction

Cardiac amyloidosis (CA) is a rare and complex condition with poor prognosis. Novel therapies have been shown to improve outcome, however, most of the affected individuals remain undiagnosed, mainly due to a lack in awareness among clinicians. One approach to overcome this issue is to use automated diagnostic algorithms that act based on routinely available laboratory results.

Purpose

We tested the performance of flexible machine learning and traditional statistical prediction models for non-invasive CA diagnosis based on routinely collected laboratory parameters. Since laboratory routines vary between hospitals or other health care providers, special attention has been taken to adaptive and dynamic parameter selection, and to dealing with the frequent occurrence of missing values.

Methods

Our cohort consisted of 376 clinically accepted patients with various types of heart failure. Of these, 69 were diagnosed with CA via endomyocardial biopsy (positives), and 307 had unrelated cardiac disorders (negatives). A total of 63 routine laboratory parameters were collected from these patients, with a high incidence of missing values (on average 60% of patients for each parameter). We tested the performance of two prediction models: logistic regression, and extreme gradient boosting with regression trees. To deal with missing values we adopted two strategies: a) finding an optimal overlap of parameters and deleting all patients with missing values (reduction of parameters and samples), and b) retaining all features and imputing missing values with parameter-wise means. To fairly assess the performance of prediction models we employed a 10-fold cross validation (stratified to preserve sample class ratio). Finally, area under curve for receiver-operator characteristic (ROC AUC) was used as our final performance measure.

Results

A complex machine learning model based on forests of regression trees proved to be the most performant (ROC AUC 0.94±4%) and robust to missing values. The best regression model was obtained with the 25 most frequent variables and patient deletion in case of missing values (ROC AUC 0.82±0.8%). While progressive inclusion of predictor variables worsened the performance of the logistic regression, it increased that of the machine learning approach.

Conclusions

Extreme gradient boosting of regression trees by routine laboratory parameters achieved staggering accuracy results for the automated diagnosis of CA. Our data suggest that implementations of such algorithms as independent interpreters of routine laboratory results may help to establish or suggest the diagnosis of CA in patients with heart failure symptoms, even in the absence of specialized experts.

P5258Native T1 time of right ventricular insertion points by CMR: relation with invasive hemodynamics and outcome in HFPEF

Background

Increased afterload to the right ventricle (RV) has been shown to induce myocardial fibrosis at the RV insertion points (RVIPs). Such changes can be discrete but potentially detected by cardiac magnetic resonance (CMR) T1-mapping. Whether RVIP fibrosis is associated with prognosis in heart failure with preserved ejection fraction (HFpEF) is unknown.

Methods

We prospectively investigated 167 consecutive HFpEF patients, a population frequently suffering from postcapillary pulmonary hypertension (PH), who underwent CMR including T1-mapping. 92,8% also underwent right heart catheterization for hemodynamic assessment. Kaplan–Meier analysis, cox regression analysis and Spearman's rank order correlation were applied as statistical methods. The parameter with the strongest discriminative power of each group (clinical, hemodynamic and CMR) by receiver operating curve analysis was selected to the enter the multivariate cox model.

Results

Native T1 times were 995±73 ms at the anterior and 1040±90 ms at the inferior RVIP. By Spearman's rank order testing, RVIP T1 times were significantly correlated with pulmonary artery pressure (mean PAP, r=0.313 and 0.311 for anterior and inferior RVIP, respectively), pulmonary artery wedge pressure (r=0.301 and 0.251) and right atrial pressure (r=0.245 and 0.185; p for all<0.05). During a mean follow-up of 43.2±22.6 months, 30 (18.0%) subjects died. By multivariable Cox regression, NTproBNP (Hazard ratio [HR] 2.105, 95% confidence interval [CI] 1.332–3.328; p=0.001), systolic PAP (HR 1.618, 95% CI 1.175–2.230; p=0.003), and native T1 time of the anterior RVIP (HR 1.659, 95% CI 1.125–2.445; p=0.011) were significantly associated with outcome. Also, by Kaplan-Meier analysis, T1 time at the anterior RVIP had a significant effect on survival (log-rank, p=0.002).

Kaplan Meier Curve

Conclusions

Interstitial expansion of the anterior RVIP as detected by CMR T1-mapping reflects hemodynamic alterations, and is independently related with prognosis in HFpEF.

6099Impact of aortic valve replacement on outcomes of patients with low-flow, low-gradient moderate aortic stenosis

Background

Aortic valve replacement (AVR) is recommended for patients with low-flow, low-gradient (LFLG) and true-severe aortic stenosis (TSAS). However, there is very few data on the potential benefit of AVR in patients with LFLG pseudo-severe (i.e. moderate) AS (PSAS).

Methods

Consecutive patients with aortic valve area ≤0.6 cm2/m2, mean gradient <40 mmHg were prospectively recruited in a multicenter observational cohort study. The patients were categorized in TSAS vs. PSAS using previously reported thresholds of flow-independent parameters of AS severity (projected valve area at normal flow rate ≤1.0 cm2 and/or aortic valve calcium score by CT >1200 AU in women and >2000 AU in men). To account for between-treatment-group differences, inverse probability-of-treatment weighting was combined to Cox proportional hazards regression.

Results

Among the 430 patients included in this study, 297 (69%) were classified as TSAS and 274 (57%) underwent AVR. Of note, 21% of the patients treated by AVR were classified as PSAS. In patients managed conservatively (ConsRx), 52% had PSAS and 48% TSAS. During a median follow-up of 28 months [8–60], 198 patients died. The adjusted weighted hazard ratio (awHR) of death associated with AVR as compared to ConsRx was 0.42 [0.24–0.73] (p<0.0001, Figure1-Panel-A). This survival benefit associated with AVR was observed not only in patients with TSAS but also in those with PSAS (awHR: 0.29 [0.12–0.70]; p=0.006, Figure1-Panel-B).

Figure 1

Conclusion

The results of this study suggest that AVR is associated with a survival benefit not only in LFLG patients with TSAS but also in those with PSAS. Randomized trials are needed to confirm the benefit of AVR in patients with moderate AS and depressed LV systolic function.

Acknowledgement/Funding

Canadian Institute of Health Research

P605Correlation of left atrial phasic transport function and arrhythmogenic substrate in patients with atrial fibrillation: cardiac magnetic resonance feature tracking and bipolar voltage mapping

Background

Bipolar voltage mapping is a widely accepted approach to identify areas of arrhythmogenic substrate in patients presenting for atrial fibrillation (AF) ablation.

However, until now little is known about the correlation of left atrial (LA) bipolar voltage distribution and LA transport function.

Purpose

To study the impact of LA low voltage zones (LVZ) on LA transport function.

Methods

107 consecutive patients presenting for ablation of symptomatic AF (34 paroxysmal AF, 73 persistent AF) were prospectively enrolled. Each patient underwent cardiac magnetic resonance imaging (CMR) within 24 hours prior to the ablation procedure. 59 patients were in sinus rhythm (SR) and 48 in AF. LA phasic indexed volumes (LAVi) and ejection fractions were calculated using biplane area length formula. In addition LA phasic strains and strain rates were analyzed using dedicated software (Figure 1A & B).

LA bipolar voltage mapping was performed prior to beginning of ablation in sinus rhythm using a 3-dimensional mapping system and LVZ were defined as areas of bipolar voltage <0.5mV.

Results

LVZ were present in 47 patients (23 in SR). The area of LVZ was 14.6cm2 (5.3–34.0). For patients in AF at the time of CMR only elevated minimal and maximal LAVi (p=0.001 and p=0.002 respectively) but no LA functional parameter was predictive for the occurrence of LVZ. In contrast for patients in SR all LA phasic volumes (endsystolic, pre atrial contraction and enddiastolic LAVi) and LA function parameters (passive, active and total ejection fraction (EF), reservoir, conduit and booster pump strains and strain rates) were predictive for the occurrence of LVZ. After clustered and pooled multivariate logistic regression only impaired booster pump strain rate was still predictive for occurrence of LVZ (OR 0.974, 95% CI 0.950–0.998, p=0.036).

In addition Pearson correlation analysis revealed a strong link between LA booster pump functional parameters and cm2 expansion of LVZ areas: LA active EF, LA booster pump strain and SR (r=−0.42, p=0.044; r=−0.47, p=0.024; r=−0.65, p=0.001 [Figure 1C] respectively).

Conclusion

For patients in SR LA transport function is closely linked to the occurrence of LA LVZ and outperforms LA volumetric measurements for the prediction of LA LVZ.

Furthermore LA booster pump function parameters show robust correlation to the extension of LA LVZ.

P5573Disproportionate functional mitral regurgitation: advancing a conceptual framework from bench to bedside

Introduction

A recently proposed conceptual framework seeks to rearrange the effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) cut-offs according to left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) in functional mitral regurgitation introducing “disproportionate FMR” to describe clinically meaningful FMR. The conceptual framework, however, remains hypothetical.

Purpose

To test the significance of disproportionate FMR.

Methods

Data of 291 heart failure patients with reduced ejection fraction (HFrEF) under guideline directed therapy were embedded into this conceptual framework (Figure 1A). The black line represents the relationship when the degree of FMR is proportionate to LVEDV with a regurgitant fraction of (RegFrac) of 50%. The dashed lines represent the degree of uncertainty determined by the imprecision inherent to the measurement of RegFrac defined as 2SD for inter- and intraobserver variability by Bland-Altmann analysis (equals ±6.6%). Cox-regression and Kaplan-Meier analysis were applied to assess the association between FMR proportionality and mortality.

Results

Median age was 68 years (IQR 61–75), 77% were male. Median LVEF was 25% (IQR 18–33) and LVEDV was 214ml (IQR 165–267). Disproportionate FMR was present in 71 patients (24%) (red dots Figure 1A) with a median EROA of 0.26cm2 (IQR 0.18–0.34) and a median RegVol of 42ml (IQR 28–52), proportionate FMR (yellow dots Figure 1 A) in 81 patients (28%) with a median EROA of 0.12cm2 (IQR 0.09–0.17) and a median RegVol of 18ml (IQR 14–27). During 7-years follow-up, 166 patients died. Disproportionate FMR was associated with excess mortality compared to patients with non-severe FMR (HR 1.97, 95% CI 1.04–0.71, P<0.001), whereas proportionate FMR was not associated with increased long-term mortality (HR 1.04, 95% CI −1.53–0.71, P=0.83, Figure 1B).

Figure 1. Panel A and B

Conclusion

Every fifth patient suffers from disproportionate FMR which conveys a two-fold increased risk of mortality. Disproprtionate FMR corresponds to an EROA of roughly 0.3cm2 and a RegVol of 45ml – the unifying intersection between ESC and ACC/AHA guidelines to define severe FMR. The RegFrac provides a measure proportionated to left ventricular size and function supporting its use to define clinically relevant FMR. However, RegFrac is subject to compound error due to imputation of multiple measurements limiting its use as the leading contender for FMR grading. Regardless of the term used to describe clinically significant FMR, the conceptual framework emphasizes the unmet clinical need for recalibrated cut-offs for FMR severity condensed to an algorithm that combines the strengths of several measurements of FMR severity in an integrated manner.

131Left atrial phasic function in heart failure with preserved ejection fraction: cardiac magnetic resonance myocardial feature tracking, invasive hemodynamics and outcome

Background

Global left atrial (LA) size and function have been shown to be associated with adverse events in heart failure with preserved ejection fraction (HFpEF). The machanism of coupling from left heart failure to pulmonary circulation is still controversially discussed.

Purpose

To study the prognostic most relevant determinant of LA size and function and its backward and forward interplay.

Methods

188 HFpEF patients were prospectively enrolled and underwent baseline clinical assessment, cardiac magnetic resonance imaging (CMR) and invasive hemodynamic assessment. Coronary artery disease was ruled out by coronary angiography. 92 patients were in atrial fibrillation (AF), 96 in sinus rhythm. LA size and function were assessed by CMR including LA strain imaging by myocardial feature tracking (Figure 1A & B).

Results

Patients in AF had more pronounced dilatation of all phasic LA volumes and reduction of all phasic LA functions when compared to sinus rhythm (each p<0.001 respectively).

After 31 (9–57) months 66 patients reached the combined endpoint defined as combination from hospitalization due to heart failure and cardiovascular death. In AF no atrial functional or volume parameter was correlated to outcome. In contrast in sinus rhythm several phasic LA volume and functional parameters were associated with outcome. After multivariate cox regression analysis only reduced total LA ejection fraction and conduit strain rate were still predictive for worse outcome (p=0.031 and <0.001 respectively). After adjustment for known risk factors in HFpEF like age, six minute walking distance (6MWD), systolic pulmonary artery pressure (sPAP) and right ventricular ejection fraction as derived by CMR only impaired LA conduit strain rate remained predicitve for cardiovascular events (p=0.001). In contrast to LA booster pump function LA conduit function parameters were significantly correlated to reduced 6MWD (Figure 1C) and coupled backwards to pulmonary vasculature via correlation to sPAP and pulmonary vascular resistance (PVR) but without coupling to CMR derived elevated LV extracellular volume and left ventricular end diastolic pressure.

Conclusion

Total LA ejection fraction plays a key role in the prognosis of HFpEF. This effect seems to be mainly related to its LA conduit function but not to LA booster pump function. LA conduit function correlates to impaired 6MWD, sPAP and PVR.

P4128The right heart in patients undergoing transcatheter aortic valve replacement: insights from cardiac magnetic resonance imaging

Background

Cardiac magnetic resonance (CMR) provides the gold standard for the assessment of ventricular volumes and mass. However, data on right ventricular systolic dysfunction (RVSD) and its prognostic significance on outcome in patients undergoing transcatheter aortic valve replacement (TAVR) are lacking.

Methods

We consecutively enrolled patients with severe aortic stenosis scheduled for TAVR who underwent preprocedural CMR. Kaplan-Meier estimates and multivariate Cox-regression analysis were used to identify factors associated with outcome, including RVSD. A composite of heart failure hospitalization and/or cardiovascular death was selected as primary study endpoint.

Results

145 consecutive patients (80.5±7.6 years; 51.7% female) were prospectively included, 25 (17.2%) of which had RVSD defined as RV ejection fraction (RVEF) <40%. RVSD was significantly associated with male sex, atrial fibrillation, reduced left ventricular (LV) EF (<50%) and RV endsystolic volume on CMR (all p<0.05). Serum NT-proBNP (14065±12042 vs. 3203±4615 ng/ml; p<0.001) and creatinine levels (1.59±0.96 vs. 1.29±1.03 mg/dl; p=0.201) were elevated in patients with RVSD. A total of 27 events occurred during follow-up (29±13 weeks). While LVSD was not significantly associated with outcome (p=0.654), RVSD showed a strong and independent association with event-free survival in the multivariate Cox-regression analysis [hazard ratio 3.836 (95% confidence interval 1.670–8.810); p=0.002], which included all relevant CMR parameters, cardiovascular risk factors and routine biomarkers.

Conclusions

RVSD rather than LVSD, as determined by CMR, is an important predictor of outcome in patients undergoing TAVR. RV function might thus add useful prognostic information on top of established risk factors.

Aortic valve stenosis awareness in Austria-results of a nationwide survey in 1001 subjects

Despite the prognostic significance of severe aortic valve stenosis, knowledge is limited in the general population. To document the status quo for Austria, knowledge about valvular heart disease/aortic valve stenosis was documented in 1001 participants >60 years of age. 6.7% of respondents were knowledgeable of aortic valve stenosis, with 1.6% being concerned about the condition (24.1% cancer, 18.8% Alzheimer’s disease, 15.1% stroke). 29.5% were familiar with valvular heart disease (76.7% heart attack, 36.9% stroke). Only 1/3 reported auscultation by their general practitioner (GP) at least every third visit. Typical symptoms of aortic valve stenosis were likely to be reported by 50%. After exposure to further information on aortic valve stenosis, only 20% reported to be more concerned and ready to obtain more disease-related information. Awareness of surgical and catheter-based treatment options was claimed by 77% of respondents. Awareness campaigns on valvular heart disease are warranted to improve patient care in Austria.

Native T1 time of right ventricular insertion points by cardiac magnetic resonance: relation with invasive haemodynamics and outcome in heart failure with preserved ejection fraction

Aims

Increased afterload to the right ventricle (RV) has been shown to induce myocardial fibrosis at the RV insertion points (RVIPs). Such changes can be discrete but potentially detected by cardiac magnetic resonance (CMR) T1-mapping. Whether RVIP fibrosis is associated with prognosis in heart failure with preserved ejection fraction (HFpEF) is unknown.

Methods and results

We prospectively investigated 167 consecutive HFpEF patients, a population frequently suffering from post-capillary pulmonary hypertension, who underwent CMR including T1-mapping. About 92.8% also underwent right heart catheterization for haemodynamic assessment.

Native T1 times were 995 ± 73 ms at the anterior and 1040 ± 90 ms at the inferior RVIP. By Spearman’s rank order testing, RVIP T1 times were significantly correlated with pulmonary artery pressure (mean PAP, r = 0.313 and 0.311 for anterior and inferior RVIP), pulmonary artery wedge pressure (r = 0.301 and 0.251) and right atrial pressure (r = 0.245 and 0.185; P for all &lt;0.05). During a mean follow-up of 43.2 ± 22.6 months, 30 (18.0%) subjects died. By multivariable Cox regression, NTproBNP [Hazard ratio (HR) 2.105, 95% confidence interval (CI) 1.332–3.328; P = 0.001], systolic PAP (HR 1.618, 95% CI 1.175–2.230; P = 0.003), and native T1 time of the anterior RVIP (HR 1.659, 95% CI 1.125–2.445; P = 0.011) were significantly associated with outcome. Also, by Kaplan–Meier analysis, T1 times at the anterior RVIPs had a significant effect on survival (log-rank, P = 0.002).

Conclusion

Interstitial expansion of the anterior RVIP as detected by CMR T1-mapping reflects haemodynamic alterations, and is independently related with prognosis in HFpEF.